Encode the Clang branch and Subversion revision into a PCH file, and

assume that PCH files from different Clang revisions are not
compatible. Addresses <rdar://problem/7266572>.

llvm-svn: 83323

1 files changed, 13 insertions, 1 deletions

diff --git a/clang/lib/Frontend/PCHWriter.cpp b/clang/lib/Frontend/PCHWriter.cpp
index 08a1661e1d3..64a678ea450 100644
--- a/clang/lib/Frontend/PCHWriter.cpp
+++ b/clang/lib/Frontend/PCHWriter.cpp
@@ -394,7 +394,8 @@ void PCHWriter::WriteBlockInfoBlock() {
   RECORD(STAT_CACHE);
   RECORD(EXT_VECTOR_DECLS);
   RECORD(COMMENT_RANGES);
-
+  RECORD(SVN_BRANCH_REVISION);
+  
   // SourceManager Block.
   BLOCK(SOURCE_MANAGER_BLOCK);
   RECORD(SM_SLOC_FILE_ENTRY);
@@ -564,6 +565,17 @@ void PCHWriter::WriteMetadata(ASTContext &Context, const char *isysroot) {
     Record.push_back(pch::ORIGINAL_FILE_NAME);
     Stream.EmitRecordWithBlob(FileAbbrevCode, Record, MainFileNameStr);
   }
+  
+  // Subversion branch/version information.
+  BitCodeAbbrev *SvnAbbrev = new BitCodeAbbrev();
+  SvnAbbrev->Add(BitCodeAbbrevOp(pch::SVN_BRANCH_REVISION));
+  SvnAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // SVN revision
+  SvnAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // SVN branch/tag
+  unsigned SvnAbbrevCode = Stream.EmitAbbrev(SvnAbbrev);
+  Record.clear();
+  Record.push_back(pch::SVN_BRANCH_REVISION);
+  Record.push_back(getClangSubversionRevision());
+  Stream.EmitRecordWithBlob(SvnAbbrevCode, Record, getClangSubversionPath());
 }
 
 /// \brief Write the LangOptions structure.